Method for manufacturing a chemically adsorbed film and a chemical adsorbent solution for the method

ABSTRACT

The methods of forming a chemically adsorbed film by contacting a substrate with a solution mixture containing an alkoxysilane surface active agent, a non-aqueous solvent and a silanol-condensing catalyst to form a film covalently bonded to the substrate via siloxane bonds. These methods do not generate hydrochloric acid gas in forming the films and allow practical reaction rates.

This application is a division of Ser. No. 08/661,734, filed Jun. 11,1996, now U.S. Pat. No. 5,849,369.

FIELD OF THE INVENTION

This invention relates to a method for manufacturing a chemicallyadsorbed film on the surface of a substrate comprising active hydrogensvia siloxane bonding and a chemically adsorbent solution for usingtherefor. More particularly, this invention relates to a method formanufacturing a chemically adsorbed film using an alkoxysilane surfaceactive agent, a nonaqueous solvent and a silanol condensing catalyst anda chemical adsorbent solution using therefor.

BACKGROUND OF THE INVENTION

The surface of the substrate such as plastic, metal, ceramics, fiber,woods, concrete, paint or the like have been treated for improved use ina variety of fields. For example, a method for treating a surfacecontaining macromolecules includes; coating with a fluorosilane couplingagent to provide water and oil repellancy; coating with a wax to providelubrication; coating with a polyvinyl alcohol to provide hydrophilicity;and coating with a suspension of a fluorocarbon-based polymer in ordernot to catch dirt on the surface of a substrate. The above-mentionedmethods are recognized in the field.

However, coating films of the prior art have a relatively weak bindingstrength to the substrates containing macromolecules. Consequently, ifthe substrates are wiped by a cloth or washed repeatedly, coating filmsare peeled off from the substrate and lose the finishing effect.Moreover, coating films of the prior art have a large number ofpin-holes on their surfaces because molecules arrange in variousdirections therein, thus deteriorating the property. Moreover,fluorocarbon-based polymer coating films are deficient in transparencyso that they cannot be used for the treatment of optical materials thatrequire transparency.

Methods for manufacturing chemically adsorbed monomolecular films aresuggested by the inventor of this invention. See, for example, JapaneseLaid-Open Patent No. (Tokkai-Hei) 4-132637, Japanese Laid-Open PatentNo. (Tokkai-Hei) 4-221630, Japanese Laid-Open Patent No. (Tokkai-Hei)4-367721 which are incorporated by reference. Such films are free frompeeling off from the substrates, being pin-hole free, having thicknesson the order of nanometers, and having a high transparency, in otherwords, transparency and lustering properties.

However, according to the conventional method for manufacturingchemically adsorbed films, the films were formed by a dehydrochloricreaction between a chlorosilane-based surface active agent and thesurface of a substrate. Consequently, harmful hydrochloric acid gas cangenerate during the formation of such films. Also certain methods haveattempted to form films by a dealcohol reaction by way of analkoxysilane surface active agents. However, since this reactionproceeds slowly, films are not easily formed. The method of using adealcohol catalyst is also possible, but the surface active agentcross-links with the moisture content in the air and loses the activityif only the dealcohol catalyst is added. In other words, if thefinishing agent includes moisture, the surface active agent cross-linksbefore reacting to the surface of the substrate so that the reaction atthe interface of solid and liquid is prevented, thus making chemicallyadsorption difficult.

SUMMARY OF THE INVENTION

To solve the above-noted problems, the invention aims to provide amethod of forming a chemically adsorbed film which allows practicalreaction rates and does not generate hydrochloric acid gas in formingthe films.

To attain the above aim, the invention provides a first method offorming a chemically adsorbed film on a substrate having an activehydrogen, comprising the step of contacting the substrate with asolution mixture containing an alkoxysilane surface active agent, anactive hydrogen-free nonaqueous solvent and silanol condensing catalystto form a chemically adsorbed film covalently bonded to a surface of thesubstrate via siloxane bonding. The term "active hydrogen-freenonaqueous solvent" relates to a nonaqueous solvent containingsubstantially no active hydrogen. Preferably, it is free of all activehydrogen. The nonaqueous solvents can include any solvents other thanwater.

The first method can comprise contacting the substrate with the solutionmixture containing the alkoxysilane surface active agent, the activehydrogen-free nonaqueous solvent and the silanol condensing catalyst,covalently bonding the alkoxysilane surface active agent to the surfaceof the substrate via a siloxane bond, and washing the substrate with anonaqueous solvent to form a monomolecular coating film covalentlybonded to the surface of the substrate via a siloxane bond. This methodefficiently forms a monomolecular film made from the surface activeagent, and the film is covalently bonded to the surface of the substratevia siloxane bonds.

The first method can also comprise contacting the substrate with asolution mixture containing the alkoxysilane surface active agent, theactive hydrogen-free non aqueous solvent and the silanol condensingcatalyst, covalently bonding the alkoxysilane surface active agent tothe surface of the substrate via siloxane bonds, evaporating thenonaqueous solvent, and subjecting the substrate and the alkoxysilanesurface active agent to a reaction with water to form a coating of apolymer film covalently bonded to the surface of the substrate viasiloxane bonds. This method efficiently forms a polymer coating filmmade from the surface active agent, and the film is covalently bonded tothe surface of the substrate via siloxane bonds.

The invention further provides a second method comprising the steps ofcontacting the substrate with a solution mixture containing a firstalkoxysilane surface active agent, an active hydrogen-free nonaqueoussolvent and a silanol condensing catalyst to form an inner layer whichis a siloxane chemically adsorbed film covalently bonded to a surface ofthe substrate via a siloxane bond, and contacting the inner layer with asolution mixture containing at least a second alkoxysilane surfaceactive agent, an active hydrogen-free nonaqueous solvent and a silanolcondensing catalyst to form an outer layer made from a secondalkoxysilane surface active agent and covalently bonded to a surface ofthe inner layer via a siloxane bond. In this embodiment, the firstalkoxysilane surface active agent is preferably at least one selectedfrom the group consisting of hexaalkoxy disiloxane, octaalkoxytrisiloxane, dialkoxysilane, trialkoxysilane and tetraalkoxysilane. Thismethod efficiently forms a bi-layer chemically adsorbed film having aninner layer which is a chemically adsorbed monomolecular film ofsiloxane and an outer layer which is a chemically adsorbed monomolecularfilm from the second alkoxysilane surface active agent.

The second method can comprise contacting the substrate with thesolution mixture containing the first alkoxysilane surface active agent,the active hydrogen-free nonaqueous solvent and the silanol condensingcatalyst, covalently bonding the first alkoxysilane surface active agentto the surface of the substrate via a siloxane bond, washing thesubstrate with a nonaqueous solvent to form the inner layer whichcomprises a siloxane and is a chemically adsorbed monomolecular filmcovalently bonded to a surface of the substrate via a siloxane bond andthen contacting the substrate covered with the inner layer with asolution mixture containing the second alkoxysilane surface activeagent, the active hydrogen-free nonaqueous solvent and the silanolcondensing catalyst, covalently bonding the second alkoxysilane surfaceactive agent to the surface of the inner layer via a siloxane bond, andwashing the substrate with a nonaqueous solvent to form an outer layermade from the second alkoxysilane surface active agent and covalentlybonded to a surface of the inner layer via a siloxane bond. The firstalkoxysilane surface active agent is preferably at least one selectedfrom the group consisting of hexaalkoxy disiloxane, octaalkoxytrisiloxane, dialkoxysilane, trialkoxysilane and tetraalkoxysilane. Thismethod efficiently forms a chemically adsorbed bi-layer film having aninner layer which is a chemically adsorbed monomolecular film made fromsiloxane and an outer layer which is a chemically adsorbed monomolecularfilm made from a second alkoxysilane surface active agent.

The second method can also comprise contacting the substrate with asolution mixture containing the first alkoxysilane surface active agent,the active hydrogen-free nonaqueous solvent and the silanol condensingcatalyst, covalently bonding the first alkoxysilane surface active agentto the surface of the substrate via a siloxane bond, washing thesubstrate with a nonaqueous solvent to form a siloxane inner layer andcovalently bonded to a surface of the substrate via a siloxane bond andthen, contacting the substrate with a solution mixture containing atleast the second alkoxysilane surface active agent, the activehydrogen-free nonaqueous solvent and the silanol condensing catalyst,covalently bonding the second alkoxysilane surface active agent to thesurface of the inner layer via a siloxane bond, evaporating thenonaqueous solvent on the substrate, and subjecting an alkoxy group inthe second alkoxysilane surface active agent remaining on the surface ofthe inner layer to a reaction with water to form an outer layer madefrom the second alkoxysilane surface active agent and covalently bondedto a surface of the inner layer via a siloxane bond. The firstalkoxysilane surface active agent is preferably at least one selectedfrom the group consisting of hexaalkoxy disiloxane, octaalkoxytrisiloxane, dialkoxysilane, trialkoxysilane and tetralkoxysilane. Thismethod efficiently forms a bi-layer chemically adsorbed film having aninner layer which is a chemically adsorbed monomolecular film ofsiloxane and an outer layer which is a chemically adsorbed polymer filmfrom the second alkoxysilane surface active agent.

The second method can also comprise contacting the substrate with asolution mixture containing the first alkoxysilane surface active agent,the active hydrogen-free nonaqueous solvent and the silanol condensingcatalyst, covalently bonding the first alkoxysilane surface active agentto the surface of the substrate via a siloxane bond, evaporating thenonaqueous solvent on the substrate, subjecting an alkoxy group in thesecond alkoxysilane surface active agent remaining on the surface of thesubstrate to a reaction with water to form an inner layer whichcomprises a polysiloxane and is a film covalently bonded to a surface ofthe inner layer via a siloxane bond, contacting the substrate with thesolution mixture containing at least the second alkoxysilane surfaceactive agent, the active hydrogen-free nonaqueous solvent and thesilanol condensing catalyst, covalently bonding the second alkoxysilanesurface active agent to the surface of the inner layer via a siloxanebond, and washing the substrate-and the second alkoxysilane surfaceactive agent with a nonaqueous solvent to form the outer layer made fromthe second alkoxysilane surface active agent and covalently bonded tothe surface of the substrate via a siloxane bond. The first alkoxysilanesurface active agent is preferably at least one selected from the groupconsisting of hexaalkoxy disiloxane, octaalkoxy trisiloxane,dialkoxysilane, trialkoxysilane and tetralkoxysilane. This methodefficiently forms a bi-layer chemically adsorbed film having an innerlayer which comprises polysiloxane and an outer layer which is achemically adsorbed monomolecular film from the second alkoxysilanesurface active agent.

The second method can also comprise contacting the substrate with asolution mixture containing the first alkoxysilane surface active agent,the active hydrogen-free nonaqueous solvent and the silanol condensingcatalyst, covalently bonding the first alkoxysilane surface active agentto the surface of the substrate via a siloxane bond, evaporating thenonaqueous solvent, subjecting an alkoxy group in the first alkoxysilanesurface active agent remaining on the surface of the substrate to areaction with water to form the inner layer which comprises polysiloxaneand is a film covalently bonded to the surface of the substrate via asiloxane bond, contacting the substrate with the solution mixturecontaining at least the second alkoxysilane surface active agent, theactive hydrogen-free nonaqueous solvent and the silanol condensingcatalyst, covalently bonding the second alkoxysilane surface activeagent to the surface of the inner layer via a siloxane bond, evaporatingthe nonaqueous solvent on the substrate, and subjecting an alkoxy groupin the second alkoxysilane surface active agent remaining on the surfaceof the inner layer to a reaction with water to form the outer layer madefrom the second alkoxysilane surface active agent and covalently bondedto the surface of the inner layer. The first alkoxysilane surface activeagent is preferably at least one selected from the group consisting ofhexaalkoxy disiloxane, octaalkoxy trisiloxane, dialkoxysilane,trialkoxysilane and tetralkoxysilane. This method efficiently forms abi-layer chemically adsorbed film having an inner layer which comprisespolysiloxane and an outer layer which is a polymer film from the secondalkoxysilane surface active agent.

The invention further provides a third method comprising the step ofcontacting a substrate with a solution mixture containing a silanesurface active agent, an active hydrogen-free nonaqueous solvent and asilanol condensing catalyst to form a chemically adsorbed film whichcomprises a siloxane and is covalently bonded to a surface of thesubstrate via a siloxane bond. The silane surface active agent ispreferably at least one selected from the group consisting of hexaalkoxydisiloxane, octaalkoxy trisiloxane, dialkoxysilane, trialkoxysilane andtetralkoxysilane. This method efficiently forms a hydrophilic chemicallyadsorbed thin film comprising siloxane.

The third method can comprise contacting the substrate with the solutionmixture containing the silane surface active agent, the activehydrogen-free nonaqueous solvent and the silanol condensing catalyst,covalently bonding the silane surface active agent to the surface of thesubstrate via a siloxane bond, and washing the substrate with anonaqueous solvent to form a chemically adsorbed monomolecular filmwhich comprises a siloxane and is covalently bonded to the surface ofthe substrate via a siloxane bond. The silane surface active agent ispreferably at least one selected from the group consisting of hexaalkoxydisiloxane, octaalkoxy trisiloxane, dialkoxysilane, trialkoxysilane andtetralkoxysilane. This method efficiently forms a hydrophilicmonomolecular film comprising siloxane.

The third method can also comprise contacting the substrate with thesolution mixture containing the silane surface active agent, the activehydrogen-free nonaqueous solvent and the silanol condensing catalyst,covalently bonding the silane surface active agent to the surface of thesubstrate via a siloxane bond, evaporating the nonaqueous solvent on thesubstrate, and subjecting an alkoxy group in the silane surface activeagent remaining on the surface of the substrate to a reaction with waterto form a film which comprises a polysiloxane and is a film covalentlybonded to the surface of the substrate via a siloxane bond, and thesilane surface active agent is preferably at least one selected from thegroup consisting of hexaalkoxy disiloxane, octaalkoxy trisiloxane,dialkoxysilane, trialkoxysilane and tetralkoxysilane. This methodefficiently forms a hydrophilic polymer film comprising siloxane.

The silanol condensing catalyst is preferably at least one substanceselected from the group consisting of metal carboxylate, carboxylic acidester metal salt, metal carboxylate polymer, metal carboxylate chelate,titanic ester and titanic ester chelate. These catalysts have goodcatalytic activity. Examples of such catalysts include tin (I) acetate,dibutyl tin dilaurate, dibutyl tin dioctate, dibutyl tin diacetate,dioctyl tin dilaurate, dioctyl tin dioctate, dioctyl tin diacetate, tin(I) dioctanate, lead naphthenate, cobalt naphthenate, iron 2-ethylhexenoic acetate, dioctyl tin bis-octyl thioglycollic acid ester salt,dioctyl tin maleic acid ester salt, dibutyl tin maleic acid polymer,dimethyl tin mercapto propionic acid salt polymer, dibutyl tinbis-acetyl acetonate, dioctyl tin bis-acetyl laurate, tetrabutyltitanate, tetranonyl titanate and bis-(acetylacetonyl)di-propyltitanate. The catalysts can be used either alone or incombination.

The silane surface active agent preferably comprises a fluorocarbongroup. Such silane surface active agents comprising a fluorocarbon groupprovides secondly formed, e.g., outer layers with properties of water,oil and dirt repellancy. Examples of such silane surface active agentsinclude substances represented by one formula selected from thefollowing two formulas:

    CF.sub.3 --(CF.sub.2).sub.n --(R).sub.m --SiX.sub.p (OA).sub.3-p

wherein n is 0 or an integer, R represents an alkylene group, vinylenegroup, ethynylene group, arylene group, or a substituent containing asilicon atom or oxygen atom, m is 0 or 1, X represents an hydrogen atom,alkyl group, alkoxy group, fluorine-containing alkyl group orfluorine-containing alkoxy group, A represents an alkyl group, and p isan integer of 0, 1 or 2; and

    CF.sub.3 COO--(CH.sub.2).sub.w --SiX.sub.p (OA).sub.3-p

wherein w is an integer, X represents an hydrogen atom, alkyl group,alkoxy group, fluorine-containing alkyl group or fluorine-containingalkoxy group, A represents an alkyl group, and p is an integer of 0, 1or 2.

The substrate preferably comprises at least one material selected fromthe group consisting of metal, ceramic, glass, plastic, paper, fabricand leather. When formed of, e.g., plastic or synthetic fiber fabric,the substrate preferably has been made hydrophilic by treating thesubstrate either with a plasma containing oxygen or in a coronaatmosphere. The treatment allows molecules of the surface active agentsto fix on the substrates in high concentrations.

The nonaqueous solvent is preferably a water-free solvent comprising ahydrocarbon or a water-free solvent comprising a fluorocarbon.Fluorocarbon-based solvents, especially, are easy to use because theyare less harmful. The term "water-free solvent" relates to a solventcontaining substantially no water.

The invention further provides a chemical adsorbent solution comprisinga solution mixture containing an alkoxysilane surface active agent, anactive hydrogen-free nonaqueous solvent and a silanol condensingcatalyst. The chemical adsorbent solution can contain other ingredientsas long as the ingredient does not inhibit catalytic reaction.

The silanol condensing catalysts disclosed above are also available forthe chemical adsorbent solution of the invention.

The chemical adsorbent solution of the invention can also contain thealkoxysilane surface active agent comprising a fluorocarbon group,specifically substances represented by one formula selected from theabove-mentioned two formulas.

The chemical adsorbent solution of the invention can also containnonaqueous solvents selected from, for example, water-free solventscomprising a hydrocarbon and a water-free solvent comprising afluorocarbon, and silicone solvents or the mixture.

The chemical adsorbent solution of the invention preferably has a watercontent of 10 ppm or less. The low water content is helpful for keepingstabilities of alkoxysilane surface active agents and silanol condensingcatalysts and for keeping pot life of the chemical adsorbent solution.

It is preferable in the chemical adsorbent solution of the inventionthat 100 weight parts of the solution mixture comprises 0.1 to 30 weightparts of the alkoxysilane surface active agent, 0.0001 to 7.5 weightparts of the silanol condensing catalyst, and 62.5 to 99.8999 weightparts of the active hydrogen-free nonaqueous solvent.

The invention is capable of providing method for forming a chemicallyadsorbed film which allows practical reaction rates and does notgenerate acid gas in forming the films. When the surface of substratesis treated with hexaalkoxydisiloxane, octaalkoxytrisiloxane,dialkoxysilane, trialkoxysilane or tetraalkoxysilane prior to theformation of chemically adsorbed films, high density of silanol bondscan be provided on the surface of the substrates. Preferable silanolcondensing catalysts are metal carboxylate, carboxylic acid ester metalsalt, metal carboxylate polymer, metal carboxylate chelate, titanicester or titanic ester chelate. Those catalysts can be more useful thanacid catalysts in controlling reaction rate. The alkoxysilane surfaceactive agents comprising a fluorocarbon group improves water- andoil-repellent properties of the obtained coating films. In particular,substances represented by the above two formulas allow the formation ofchemically adsorbed films with high density. Further, the water-freehydrocarbon-based nonaqueous solvents or the water-freefluorocarbon-based nonaqueous solvents allow the formation of chemicallyadsorbed films with high density without decreasing catalytic activitiesof the catalysts. The fluorocarbon-based nonaqueous solvents areparticularly useful for forming polymer films because the solvents havea low specific heat and evaporate quickly.

When a substrate such as plastic and synthetic fiber fabric has littleactive hydrogen atoms on its surface, the substrate is preferablytreated either with a plasma containing oxygen or in a corona atmosphereto make the surface hydrophilic. The treatment allows the formation ofchemically adsorbed films on the surface of polymers. It was relativelydifficult for conventional methods to form chemically adsorbed films onthe polymers.

The chemical adsorbent solution of the invention realizes a usefulchemical adsorbent solution.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1(a) and 1(b) are a cross-sectional view of the surface of asubstrate, enlarged to a molecular level, explaining the process offinishing the surface in Example 1 of the invention.

FIGS. 2(a) and 2(b) are a cross-sectional view of the surface of asubstrate, enlarged to a molecular level, explaining the process offinishing the surface in Example 1 of the invention.

FIGS. 3(a), 3(b) and 3(c) are a cross-sectional view of the surface of asubstrate, enlarged to a molecular level, explaining the process offinishing the surface in Example 2 of the invention.

FIGS. 4(a), 4(b) and 4(c) are a cross-sectional view of the surface of asubstrate, enlarged to a molecular level, explaining the process offinishing the surface in Example 3 of the invention.

FIGS. 5(a), 5(b) and 5(c) are a cross-sectional view of the surface of asubstrate, enlarged to a molecular level, explaining the process offinishing the surface in Example 4 of the invention.

FIGS. 6(a), 6(b) and 6(c) are a cross-sectional view of the surface of asubstrate, enlarged to a molecular level, explaining the process offinishing the surface in Example 5 of the invention.

FIGS. 7(a), 7(b) and 7(c) are a cross-sectional view of the surface of asubstrate, enlarged to a molecular level, explaining the process offinishing the surface in Example 6 of the invention.

DETAILED DESCRIPTION OF THE INVENTION

The invention will be explained in detail with reference to the attachedfigures and following examples.

This invention can be applicable for various uses and materials such asdescribed:

(a) examples of substrates--metal, ceramics, plastic, wood, stone (theinvention being applicable even when the substrate surface is coatedwith paint or the like in advance);

(b) examples of cutlery--kitchen and other knives, scissors, engraver,razor blade, hair clippers, saw, plane, chisel, gimlet, badkin, cuttingtools, drill tip, blender blade, juicer blade, flour mill blade, lawnmower blade, punch, straw cutter, stapler, blade for can opener,surgical knife or the like;

(c) examples of needles--acupuncture needle, sewing needle,sewing-machine needle, long thick needle for making tatami, syringeneedle, surgical needle, safety pin or the like;

(d) examples of products in the pottery industry--products made ofpottery, glass, ceramics or enameled products, including hygienicpotteries (such as a chamber pot, wash-bowl, bathtub, etc.), tableware(such as a rice bowl, plate, bowl, teacup, glass, bottle, coffee-pot,pots and pans, earthenware mortar, cup, etc.), flower vases (such as aflower bowl, flowerpot, small flower vase, etc.), chemistry apparatus(such as a beaker, reacter vessel, test tube, flask, culture dish,condenser, stirring rod, stirrer, mortar, vat, syringe), roof tile,tile, enameled tableware, enameled wash bowl, and enameled pots andpans;

(e) examples of mirrors--hand mirror, full-length mirror, bathroommirror, washroom mirror, mirrors for automobile (back and side mirrors),half mirror, mirror for show window, mirrors for department store or thelike;

(f) examples of molding parts--die for press molding, die for castmolding, die for injection molding, die for transfer molding, die forvacuum molding, die for blow forming, die for extrusion molding, die forinflation molding, die for fiber spinning, calender processing roll;

(g) examples of ornaments--watch, jewelry, pearl, sapphire, ruby,emerald, garnet, cat's-eye, diamond, topaz, bloodstone, aquamarine,turquoise, agate, marble, amethyst, cameo, opal, crystal, glass, ring,bracelet, brooch, tiepin, earrings, necklace, glasses frames (ofpatinum, gold, silver, aluminum, titanium, tin, compound metals of theseelements, or stainless steel) or the like;

(h) examples of molds for food--cake mold, cookie mold, bread mold,chocolate mold, jelly mold, ice cream mold, oven plate, ice tray or thelike;

(i) examples of cookware--pots and pans, iron pot, kettle, pot, fryingpan, hot plate, net for grilling food, tool for draining off oil, platefor making takoyaki or the like;

(j) examples of paper--photogravure paper, water and oil repellentpaper, paper for posters, high-quality paper for pamphlets or the like;

(k) examples of resin--polyolefin (such as polypropylene, polyethylene,etc.), polyvinylchloride, polyvinylidenechloride, polyamide, polyimide,polyamideimide, polyester, aromatic polyester, polystyrene, polysulfone,polyethersulfone, polyphenylenesulfide, phenolic resin, furan resin,urea resin, epoxide, polyurethane, silicon resin, ABS resin, methacrylicresin, ethylacrylate resin, ester resin, polyacetal, polyphenyleneoxideor the like;

(l) examples of household electric goods--television, radio, taperecorder, audio goods, CD player, refrigerator, freezer, airconditioner, juicer, blender, blade of an electric fan, lightingequipment, dial plate, hair drier for perm or the like;

(m) examples of sporting goods--skis, fishing rod, pole for pole vault,boat, sailboat, jet skis, surfboard, golf ball, bowling ball, fishingline, fishing net, fishing float or the like;

(n) examples of vehicle parts;

(1) ABS resin--lamp cover, instrument panel, trimming parts, andprotector for a motorcycle,

(2) cellulose plastic--markings for automobile, and steering wheel,

(3) FRP (Fiber Reinforced Plastics)--bumper, and engine cover,

(4) phenolic resin--brake,

(5) polyacetal--wiper, wiper gear, gas valve, carburetor parts,

(6) polyamide--radiator fan,

(7) polyarylate (polycondensation polymerization by bisphenol A andpseudo phthalic acid)--direction indicator lamp (or lens), cowl boardlens, relay case,

(8) polybutylene terephthalate--rear end, front fender,

(9) poly amino-bismaleimide--engine parts, gear box, wheel, suspensiondrive system,

(10) methacrylate resin--lamp cover lens, meter panel and cover, andcenter mark,

(11) polypropylene--bumper,

(12) polyphenylene oxide--radiator grill, wheel cap,

(13) polyurethane--bumper, fender, instrument panel, and fan,

(14) unsaturated polyester resin--body, gas tank, heater housing, meterpanel,

(o) examples of stationary goods--fountain pen, ballpoint pen,mechanical pencil, pencil case, binder, desk, chair, book shelf, rack,telephone base, ruler, draftsman's outfit or the like;

(p) examples of building materials--roof materials (such as ceramictile, slate, tin such as used in galvanized iron plate, etc.), outerwall materials (such as wood including processed wood, mortar, concrete,ceramic sizing, metallic sizing, brick, building stone, plasticmaterial, metallic material including aluminum, etc.), interiormaterials (such as wood including processed wood, metallic materialincluding aluminum, plastic material, paper, fiber, etc.) or the like;

(q) examples of stone materials--granite, marble or the like, used forbuilding, building material, works of art, ornament, bath, gravestone,monument, gatepost, stone wall, sidewalk, paving stone, etc.

(r) examples of musical instruments and audio apparatus--percussioninstruments, string instruments, keyboard instruments, woodwindinstruments, brass instruments or the like, more specifically, drum,cymbals, violin, cello, guitar, koto, piano, flute, clarinet,shakuhachi, horn, etc., and microphone, speaker, earphone or the like.

(s) others--high voltage insulator with good water, oil andcontamination repelling properties, including thermos bottles, vacuumapparatus, insulator for transmitting electricity, spark plugs or thelike.

The invention will be explained in detail with reference to the attachedfigures and following examples. In the following Examples, % representswt. %.

EXAMPLE 1

Chemically adsorbed monomolecular films 3 was formed by the followingprocedures:

preparing a blue glass plate 1 comprising active hydrogen on its surfaceand washing it with alkali detergent or the like and then degreasing bywashing it in water (FIG. 1(a));

soaking the prepared glass plate 1 in chemical adsorbent solutionconsisting of CF₃ (CF₂)₇ (CH₂)₂ Si(OCH₃)₃ containing fluorocarbon group(as an alkoxysilane surface active agent) in an amount of 5%, n-dibutyltin diacetate of metal carboxylate (as a silanol condensing catalyst) inan amount of 0.1% and n-decane (as a nonaqueous liquid solventcontaining no active hydrogens) in an amount of 94.9%, in a dryatmosphere at a relative humidity of 30% or less at the room temperatureof 25° C. (the solution mixture can be heated at temperature of theboiling point of the nonaqueous solvent to be used herein ) for 2 hours;

taking the prepared glass plate out of the adsorbent solution andwashing it well with chloroform; and

reacting the substrate of the prepared glass plate to moisture contentin the air, thereby forming one layer of water and oil repellentadsorbed monomolecular film 3 having thickness of approximately 1.5 nmon the surface of the glass plate 1 via covalent bonding of Si (FIG.1(b)).

Moreover, the water and oil repelling property of the chemicallyadsorbed monomolecular film formed in the above-mentioned procedures wasexamined by measuring the contact angle. The result is shown in Table 1.As is apparent from Table 1, the water and oil repellent property of thechemically adsorbed monomolecular film which was treated by the methodfor manufacturing chemically adsorbed monomolecular film of theinvention was hardly deteriorated even after rubbed with wet cloth 50000times. According to the method of the invention, a coat having the highdurability could be obtained.

Where catalyst is included in the chemical adsorbent solution as in thisexample, at the surface where adsorbent solution contact with the glassplate, the reaction proceeded by way of the alkoxysilane group (SiOR; Rrepresents an alkyl group, e.g., a methyl group was used in thisexample) of alkoxysilane surface active agent, moisture content adsorbedto the surface of the glass plate and hydroxyl group 2 of the surfacereacted (FIG. 1(a)). The reactions proceeded by way of Formula 1 and 2:##STR1##

As a result of this treatment, at the interface between the surface ofthe glass plate and adsorbent solution, at least the alkoxysilanesurface active agent was fixed to the surface of the glass plate viacovalent bonding of Si atom, thus forming an ultra thin protecting film.As is apparent from Formula 1 and Formula 2, water plays an importantrole. In other words, if the finishing agent contains water, thefinishing agent cross-links before reacting to the surface of asubstrate. Consequently, the reaction at the interface between the solidand liquid is interrupted so that a chemically adsorbed film is notproperly formed. For this reason, the water content in the chemicaladsorbent solution should be as small as possible. It is preferable thatthe water content is not more than 10 ppm. When the reaction mentionedabove was completed, unreacted chemical adsorbent solution on the glasssurface was washed and removed by a nonaqueous solvent. Consequently,only a monomolecular film made from alkoxysilane surface active agentmolecules fixed to the surface of the glass plate via covalent bondingof Si atom remained, thus forming one layer of chemically adsorbedmonomolecular film 3.

The alkoxysilane surface active agent of the invention can includeagents represented by SiX_(p) (OA)_(4-p) (wherein X represents H, analkyl group, alkoxyl group, or a substituent comprising a fluoroalkyl orfluoroalkoxy group; A represents an alkyl group; and p represents 0, 1,2 or 3) can be used. Moreover, compounds represented by, for example,CF₃ --(CF₂)_(n) --(R)_(m) --SiX_(p) (OA)_(3-p) (wherein n represents 0or an integer; R represents an alkylene, vinylene, ethynylene, arylenegroup or a substituent comprising a silicon or oxygen atom; m represents0 or 1; and X represents H, an alkyl, alkoxyl or a substituentcomprising a fluoroalkyl or fluoroalkoxy group; A represents an alkylgroup; and p represents 0, 1 or 2) can provide a coat having anexcellent water and oil repellent property. However, other agents can beused for alkoxysilane surface active agent. Examples of the suitableagents includes: CH₃ --(CH₂)_(r) --SiX_(p) (OA)_(3-p) ; CH₃ --(CH₂)_(s)--O--(CH₂)_(t) --SiX_(p) (OA)_(3-p) ; CH₃ --(CH₂)_(u) --Si(CH₃)₂--(CH₂)_(v) --SiX_(p) (OA)_(3-p) ; CF₃ COO--(CH₂)_(w) --SiX_(p)(OA)_(3--p) ; wherein r represents 1 to 25; s represents 0 to 12; trepresents 1 to 20; u represents 0 to 12; v represents 1 to 20; wrepresents 1 to 25; X represents H, an alkyl, alkoxyl or a substituentcomprising a fluoroalkyl or fluoroalkoxy group; A represents an alkylgroup; and p represents 0, 1 or 2.

Specific examples of the agents include;

CH₃ CH₂ O(CH₂)₁₅ Si(OCH₃)₃,

CF₃ CH₂ O(CH₂)₁₅ Si(OCH₃)₃,

CH₃ (CH₂)₂ Si(CH₃)₂ (CH₂)₁₅ Si(OCH₃)₃,

CH₃ (CH₂)₆ Si(CH₃)₂ (CH₂)₉ Si(OCH₃)₃,

CH₃ COO(CH₂)₁₅ Si(OCH₃)₃,

CF₃ (CF₂)₅ (CH₂)₂ Si(OCH₃)₃,

CF₃ (CF₂)₇ --C₆ H₆ --Si(OCH₃)₃,

CH₃ CH₂ O(CH₂)₁₅ Si(OC₂ H₅)₃,

CH₃ (CH₂)₂ Si(CH₃)₂ (CH₂)₁₅ Si(OC₂ H₅)₃,

CH₃ (CH₂)₆ Si(CH₃)₂ (CH₂)₉ Si(OC₂ H₅)₃,

CF₃ (CH₂)₆ Si(CH₃)₂ (CH₂)₉ Si(OC₂ H₅)₃,

CH₃ COO(CH₂)₁₅ Si(OC₂ H₅)₃,

CF₃ COO(CH₂)₁₅ Si(OC₂ H₅)₃,

CF₃ COO(CH₂)₁₅ Si(OCH₃)₃,

CF₃ (CF₂)₉ (CH₂)₂ Si(OC₂ H₅)₃,

CF₃ (CF₂)₇ (CH₂)₂ Si(OC₂ H₅)₃,

CF₃ (CF₂)₅ (CH₂)₂ Si(OC₂ H₅)₃,

CF₃ (CF₂)₇ C₆ H₆ Si(OC₂ H₅)₃,

CF₃ (CF₂)₉ (CH₂)₂ Si(OCH₃)₃,

CF₃ (CF₂)₅ (CH₂)₂ Si(OCH₃)₃,

CF₃ (CF₂)₇ (CH₂)₂ SiCH₃ (OC₂ H₅)₂,

CF₃ (CF₂)₇ (CH₂)₂ SiCH₃ (OCH₃)₂,

CF₃ (CF₂)₇ (CH₂ )₂ Si(CH₃)₂ OC₂ H₅

CF₃ (CF₂)₇ (CH₂)₂ Si(CH₃)₂ OCH₃.

It is preferable that the content of the alkoxysilane surface activeagent in the solution mixture of the invention is 0.1-30%.

Particularly, if metal carboxylate and metal carboxylate chelate wereused, a stable chemically adsorbed film could be obtained. Moreover, thepreferable amount of silanol condensing to be added is 0.1-25% of thesurface active agent.

Only if the dealcohol reaction using alkoxy group is required to bepromoted, inorganic or organic acid can be used instead of silanolcondensing catalyst. However, as noted above, it is not preferable thatsuch acid includes water. Therefore, the silanol condensing catalyst ispreferred.

Moreover, as a nonaqueous solvent containing in no active hydrogen ispreferably selected from nonaqueous hydrocarbon-based solvents,fluorocarbon-based solvents and silicone-based solvent. Specifically, anagent having the boiling point of 100-250° C. is preferred. As otherusable solvents, the following examples can be included; petroleumnaphtha, solvent naphtha, petroleum ether, petroleum benzene,isoparaffin, n-paraffin, decalin, industrial gasoline, kerosene,ligroin, dimethylsilicone, phenylsilicone, alkyl modified silicone,polyether silicone. Moreover, as a fluorocarbon-based solvent,freon-based solvents, Fluorinert (product by 3M) and Afluid (product byAsahi Glass Co., Ltd) can be used. The above-noted examples can be usedalone or in combinations thereof.

Examples of substrates usable for the invention include substrateshaving active hydrogen, e.g., hydroxyl groups, on their surfaces.Suitable materials include metals such as Al, Cu or stainless steel, andglass, ceramics, paper, natural fiber fabric, leather and otherhydrophilic substrates. Hydroxyl groups can be introduced to the surfacehaving no hydroxyl groups, such as plastic or synthetic fiber fabric, bytreatment in a plasma atmosphere containing oxygen at 100 W for 20minutes, or a corona treatment, thus making the surface hydrophilic. Forhydrohpilic groups, in addition to hydroxyl groups (--OH), functionalgroups such as --COOH, --NH, ═NH₂ or the like can be used. However, incase that polyamide resin and polyurethane resin having imino groups(--NH) on their surfaces can be used, above-mentioned treatment is notnecessary because a dealcohol reaction is promoted between the activehydrogens of the imino groups (--NH) and the alkoxysilyl groups (--SiOA)of the chemical adsorbed film, thereby forming siloxane bonds (--SiO--).In the case that substrates are nylon or polyeurethane 11, imino groups12 containing active hydrogen are exposed on the surfaces (FIG. 2(a))and chemically adsorbed monomolecular film 13 was formed in the samemanner of the glass plate (FIG. 2(b)).

EXAMPLE 2

The polymer-state coat 23 was formed by the following procedures:

preparing a stainless steel plate 21 comprising active hydrogen on itssurface and washing it with alkali detergent or the like and thendegreasing by washing it in water (FIG. 3(a));

soaking the prepared plate in a chemical adsorbent solution, the mixtureCF₃ (CF₂)₉ (CH₂)₂ Si(OCH₃)₃ (as an alkoxysilane surface active agent) inan amount of 5%, n-dibutyl tin bis-acetyl acetonate of metal carboxylatechelate (as a silanol condensing catalyst) in an amount of 0.5% andFluorinert FC-40 (product by 3M) (as a nonaqueous liquid solventcontaining no active hydrogens) in an amount of 94.5%, in a gaseousnitrogen atmosphere for 10 minutes with heating the stainless plate 21at a temperature of 70° C. for 10 minutes;

taking the prepared substrate out of the adsorbent solution andevaporating the above-mentioned adsorbent solution remaining on thesurface of the plate, thus forming a coat 22 of alkoxysilane-basedsurface active agent containing silanol condensing catalyst on thesubstrate as in FIG. 3(b) (In this procedure, if adsorbent solution washeated, the evaporation time could be shortened.); and then

reacting the substrate to moisture content in the air, thereby formingone layer of water and oil repellent polymer coating 23 having thicknessof approximately 5 nm on the surface of the stainless steel plate viacovalent bonding of Si (FIG. 3(c)).

Moreover, the water and oil repelling property of the chemicallyadsorbed polymer film formed in this procedures was examined by the samemanner as in Example 1. The result is shown in Table 1. As is apparentfrom Table 1, the contact angle of Example 2 was somewhat inferior toExample 1, the water and oil repellent property of the chemicallyadsorbed polymer film which was treated by the method for manufacturingchemically adsorbed film of the invention was hardly deteriorated evenafter rubbed with a wet cloth 50000 times. Thus, a coating having highdurability was provided.

EXAMPLE 3

As a substrate, an acrylic resin plastic plate 31 was subjected toplasma treatment for 5 min at 300 W to clean the surface of the plateand to provide active hydrogen containing hydroxyl groups 32 (cf. FIG.4(a)). As a chemical absorbent solution, a solution mixture was preparedby using 1% of hexamethoxydisiloxane, and 98.75% of fluorocarbon-basednonaqueous solvent Fluorinert FC-40 and 0.25% of dibutyl tin dioctate asa silanol-condensing catalyst. Hexamethoxydisiloxane is an alkoxysiloxane adsorbent. The solution mixture was applied to the surface ofplastic plate 31 in dry atmosphere at a relative humidity of 25%. Theplastic plate 31 was allowed to stand for 2 h at room temperature in dryatmosphere so as to chemically adsorb hexaalkoxysiloxane onto plasticplate 31. Plastic plate 31 was washed with a fluorocarbon-basednon-aqueous solvent Fleon 113 (product by Daikin Industries Ltd). toremove excess adsorbent. Remaining unreacted alkoxy groups in theadsorbent were hydrolyzed to form an siloxane-based inner layer 33covalently bonded to plastic plate 31 via siloxane bonds (cf. FIG.4(b)). Inner layer 33 was a chemically adsorbed monomolecular film madefrom hexamethoxysiloxane. As illustrated in FIG. 4(b), the aboveprocesses provided plastic plate 31 with a number of hydroxyl groupscontaining active hydrogen.

The contact angle of water for the obtained monomolecular siloxane film33 was measured in a conventional manner, and the contact angle was 30°or less. The surface of the film 33 was found to be hydrophilic.

Secondly, another solution mixture was prepared by using alkoxysilanesurface active agent CF₃ (CF₂)₇ (CH₂)₂ Si(OCH₃)₃ in an amount of 5%,n-butyl tin diacetate as a silanol-condensing catalyst in an amount of0.1% and non-aqueous solvent containing nonactive hydrogen FluorinertFC-40 in an amount of 94.9%. N-butyl tin diacetate is a metalcarboxylate. The processed plastic plate 31 was soaked in the solutionmixture at room temperature for 12 h, in dry atmosphere at a relativehumidity of 30% or less. In the soaking process, the solution mixturecan be heated at a temperature of the boiling point of the non-aqueoussolvent used or below. Plastic plate 31 was taken out of the adsorbentsolution and washed well with the nonaqueous solvent Fluorinert FC-40 toform an outer layer 34 covalently bonded to plastic plate 31 viasiloxane bonds in high density. The outer layer was a chemicallyadsorbed monomolecular film comprising CF₃ (CF₂)₇ (CH₂)₂ Si(O--)₃ (cf.FIG. 4(c)).

The water- and oil-repellent properties of the obtained chemicallyadsorbed monomolecular accumulation layer was examined in the samemanner as in Example 1. The results of the examination are shown inTable 1. As seen from Table 1, the water- and oil-repellent propertiesof the obtained film were hardly deteriorated even after the plate wasrepeatedly rubbed with a wet cloth and washed. The obtained film wasfound to be an extremely durable coating.

Instead of the surface active agent, hexamethoxydisiloxane, other agentssuch as octaalkoxytrisiloxane, dialkoxysilane, trialkoxysilane ortetraalkoxysilane could be also used to form similar inner layers.

EXAMPLE 4

As a substrate, an aluminum plate 41, which had been subjected to thealumite processing, was washed well (cf. FIG. 5(a)). As a chemicalabsorbent solution, a solution mixture was prepared by usinghexaethoxydisiloxane in an amount of 3% and n-decane which was anon-aqueous solvent containing nonactive hydrogen in an amount of 96.5%and dioctyl tin bisoctyl thioglycollic acid ester salt as asilanol-condensing catalyst in an amount of 0.5%. The solution mixturewas applied to the surface of aluminum plate 41 in dry atmosphere atroom temperature for 2 h to chemically adsorb hexaethoxydisiloxane ontoaluminum plate 41. Aluminum plate 41 was washed with a non-aqueoussolvent, chloroform to remove an excess amount of unreacted adsorbentoff. Remaining unreacted alkoxy groups in the adsorbent were hydrolyzedto form an siloxane-based inner layer 42 covalently bonded to aluminumplate 41 via siloxane bonds (cf. FIG. 5(b)). Inner layer 42 was achemically adsorbed monomolecular film made from hexaethoxydisiloxane.As illustrated in FIG. 5(b), the above processes provided aluminum plate41 covered with a number of hydroxyl groups, that is, active hydrogen.

Secondly, another solution mixture was prepared by usingfluoroalkoxysilane surface active agent CF₃ (CF₂)₇ (CH₂)₂ Si(OC₂ H₅)₃ inan amount of 5%, dioctyl tin bisacetyl laurate in an amount of 1% andnon-aqueous solvent containing no active hydrogen Fluorinert FC-40 in anamount of 94%. Dioctyl tin bisacetyl laurate was a metal carboxylatechelate as a silanol-condensing catalyst. The solution mixture washeated to 70° C., and the above processed aluminum plate 41 was soakedin the solution mixture in dry atmosphere for 10 min. Aluminum plate 41was taken out of the adsorbent solution and the solvent in the adsorbentsolution remaining on the substrate was evaporated to form a coating ofthe fluoroalkoxysilane surface active agent containing thesilanol-condensing catalyst on the surface of the substrate. In thesoaking process, the solution mixture was heated to allow more rapidevaporation of solvents. When the substrate was taken from the solution,alkoxy groups remaining on the substrate reacted with water content inthe air to form a water- and oil-repellent coating 43 on the aluminumplate 41. The coating 43 was a polymer film covalently bonded to thesurface of the plate via siloxane bonds, and had a thickness of 7 nm(FIG. 5(c)).

The water- and oil-repellent properties of the obtained chemicallyadsorbed monomolecular accumulation layer was examined in the samemanner as in Example 1. The results of the examination are shown inTable 1. As seen from Table 1, the water- and oil-repellent propertiesof the obtained film were hardly deteriorated even after the plate wasrepeatedly rubbed with a wet cloth and washed. The obtained-film wasfound to be an extremely durable coating.

EXAMPLE 5

Polysiloxane coat 52 was formed by the following procedures:

preparing paper 51 comprising active hydrogen on its surface and dryingit well (FIG. 6(a));

soaking the prepared paper in chemical adsorbent solution, mixtureconsisting of tetramethoxydisilane (as the first alkoxysilane surfaceactive agent) in an amount of 0.5%, tetrabutyl titanate of titanic ester(as a silanol condensing catalyst) in an amount of 0.1% and Afluid (as anonaqueous liquid solvent containing no active hydrogens) in an amountof 99.4%, in a gaseous nitrogen atmosphere at the room temperature for10 minutes; and

taking the prepared paper 51 out of the adsorbent solution andevaporating the remained adsorbent solution on the surface of the paper(In this procedure, if the adsorbent solution was heated, theevaporation time could be shortened.); and

hydrolyzing the methoxy groups remained on the surface of the preparedpaper in the air, thereby forming hydrophilic polysiloxane coating film52 having thickness of approximately 4 nm on the paper surface (fibersurface) comprising a number of hydroxyl groups via covalent bonding ofSiO (FIG. 6(b)).

The contact angle of water for the obtained polymer type siloxane coat52 was measured in a conventional manner so that contact angle could notbe measured at all because of high hydrophilicity. The hydrophilicsurface was provided by providing a number of hydroxyl groups on thesurface of the paper.

Secondly, another solution mixture was prepared by using secondalkoxysilane surface active agent CF₃ (CF₂)₇ (CH₂)₂ Si(OC₂ H₅)₃ in anamount of 3%, n-dibutyl tin diacetate as a silanol-condensing catalystin an amount of 0.1%, and non-aqueous solvent containing no activehydrogen, hexadecane in an amount of 94.9%. The mixture solution wasapplied to the film 52 on the paper 51 in the nitrogen atmosphere. Paper51 was allowed to stand at the room temperature for 20 minutes. Then theapplied mixture solution was washed with chloroform to form an outerlayer 53 of chemically adsorbed monomolecular film comprising CF₃ (CF₂)₇(CH₂)₂ Si(O--)₃ covalently bonded to the surface (fiber surface) of thepaper 51 via polysiloxane bonding in high density (FIG. 6(c)).

The water and oil repellent properties of the obtained chemicallyadsorbed film were examined in the same manner as in Example 1. Theresults of the examination are shown in Table 1. As is apparent fromTable 1, the water and oil repellent properties of the obtained films ofExample 5 were high. However, the water and oil repellent propertieswere deteriorated after the paper was rubbed with a wet cloth at 10000times and washed because the substrate is paper and the surface of apaper is soft and uneven. The durability of the obtained film was alsoinferior compared to solid substrates.

EXAMPLE 6

Polysiloxane coating film 62 was formed by the following procedures:

preparing alumina plate 61 which is ceramics and washing it with alkalidetergent and degreasing it (FIG. 7(a));

applying to the prepared alumina plate chemical adsorbent solution, amixture consisting of hexamethoxydisiloxane (as the first alkoxysilanesurface active agent) in an amount of 5%, n-dibutyl tin bis-acetylacetonate of metal carboxylate chelate (as a silanol condensingcatalyst) in an amount of 0.5% and n-decane (as a nonaqueous liquidsolvent containing no active hydrogens) in an amount of 94.5%, andletting the alumina plate 61 sit for 30 minutes at the room temperature;and

evaporating the adsorbent solution remained on the surface of thealumina plate, thereby forming hexamethoxydisiloxane (In this procedure,if adsorbent solution was heated, the evaporation time could beshortened.); and

hydrolyzing the methoxy groups remained on the surface of the preparedalumina plate in the air, thereby forming a hydrophilic polysiloxanecoat 62 having thickness of approximately 5 nm on the surface of thealumina plate via covalent bonding of SiO (FIG. 7(b)).

Secondly, another chemically adsorbent solution was prepared by usingalkoxysilane surface active agent CF₃ (CF₂)₇ (CH₂)₂ Si(OC₂ H₅)₃containing fluorocarbon group in an amount of 5%, dioctyl tin bis-acetyllaurate as a silanol condensing catalyst in an amount of 1%, andnonaqueous solvent containing no active hydrogen Fluorinert FC-40 in anamount of 94%. The alumina plate was taken out of the adsorbent solutionin the air and the solution remained on the surface of the plate wasevaporated to form the coating comprising a fluoro alkoxysilane surfaceactive agent. If the adsorbent solution was heated, the evaporation ofsolvent could be quickened. Then, the prepared alumina plate was reactedto the moisture content in the air, thereby forming water and oilrepellent polymer-state coating film 63 having a thickness ofapproximately 6 nm via polysiloxane bonds (FIG. 7(c)).

Moreover, the water and oil repelling property of the chemicallyadsorbed film formed in this procedures was examined by the same manneras in Example 1. The results are shown in Table 1. As is apparent fromTable 1, the water and oil repellent property of the chemically adsorbedpolymer coat formed in Example 6 was only minimally deteriorated evenafter rubbed with a wet cloth 50000 times. Accordingly, a coating filmhaving a high durability was obtained.

COMPARATIVE EXAMPLE 1

The same experiment as in Example 1 was conducted except that thechemically adsorbent solution did not contain di-n-butyl tin diacetate:The results are shown in Table 1. The durability of the obtained coatwas practically lost after rubbed at 50000 times.

COMPARATIVE EXAMPLE 1

The same experiment as in Example 4 was directed except that dioctyl tinbis-octyl thioglycollic acid and dioctyl tin bis-acetyl laurate wasexcluded. The results are shown in Table 1. As in Reference 1,durability of the coat was significantly decreased.

                  TABLE 1    ______________________________________           Contact Angle of Water (°)                         Contact Angle of Oil (°)           Initial                  After      Initial  After           Number Rubbing Test                             Number   Rubbing Test    ______________________________________    Example 1             118      116        98     95    Example 2             113      111        94     93    Example 3             115      103        93     91    Example 4             117      115        96     93    Example 5             145      106        108    83    Example 6             115      113        95     94    Comparative             108       48        61     24    Example 1    Comparative             105       47        45     16    Example 2    ______________________________________

As is apparent from Table 1, the substrate treated with the chemicaladsorbent solution of the invention maintained its water and oilrepelling or hydrophilic property even after the surface was rubbedrepeatedly with a wet cloth. In Comparative Example 1 and ComparativeExample 2, water and oil repelling properties were low, and especiallythe properties were almost completely absent after the rubbing test.

As explained above, the methods of the invention realize a method offorming a chemically adsorbed film which allows practical reaction ratesand does not generate hydrochloric acid gas in the process of formingfilms.

According to the methods of the invention, bi-layer chemically adsorbedfilms covalently bonded to a surface of the substrate via a siloxanebond can be formed by contacting the substrate with a solution mixturecontaining an alkoxysilane surface active agent, an active hydrogen-freenon-aqueous solvent and a silanol-condensing catalyst. Further, thinfilms fixed to the substrate due to covalent bonds where substancescontaining at least one alkoxysilyl group are chemically adsorbed on thesurface of the substrate via an Si atom are safely and readily formed bycontacting the substrate with a solution mixture containing at least afirst alkoxysilane surface active agent, such as dialkoxysilane,trialkoxysilane or tetraalkoxysilane, an active hydrogen-freenon-aqueous solvent and a silanol-condensing catalyst to form an innerlayer which is a siloxane chemically adsorbed film covalently bonded toa surface of the substrate via a siloxane bond, and contacting the innerlayer on the substrate with a solution mixture containing a secondalkoxysilane surface active agent, an active hydrogen-free non-aqueoussolvent and a silanol-condensing catalyst to form an outer layer whichcomprises a molecule of the second alkoxysilane surface active agent andis a chemically adsorbed film covalently bonded to a surface of theinner layer via a siloxane bond. In other words, unlike conventionalmethods, the methods of the invention enable one to efficiently formprotection films on a variety of materials such as plastics, ceramicsand glass without generating hydrochloric acid gas in forming the films.Therefore, the invention is useful for articles necessitating anti-heat,weather and abrasion thin coatings, such as electrical appliances,household appliances, automobiles, industrial equipment, mirrors, andlenses for glasses.

The invention may be embodied in other specific forms without departingfrom the spirit or essential characteristics thereof. The embodimentsdisclosed in this application are to be considered in all respects asillustrative and not restrictive, the scope of the invention beingindicated by the appended claims rather than by the foregoingdescription, and all changes which come within the meaning and range ofequivalency of the claims are intended to be embraced therein.

What is claimed is:
 1. A chemical adsorbent solution comprising asolution mixture containing an alkoxysilane surface active agent, anactive hydrogen-free non-aqueous solvent and a silanol condensingcatalyst.
 2. The chemical adsorbent solution according to claim 1,wherein said silanol-condensing catalyst is at least one substanceselected from the group consisting of metal carboxylate, carboxylic acidester metal salt, metal carboxylate polymer, metal carboxylate chelate,titanic ester and titanic ester chelate.
 3. The chemical adsorbentsolution according to claim 1, wherein said silanol-condensing catalystis at least one substance selected from the group consisting of tin (I)acetate, dibutyl tin dilaurate, dibutyl tin dioctate, dibutyl tindiacetate, dioctyl tin dilaurate, dioctyl tin dioctate, dioctyl tindiacetate, tin (I) dioctanate, lead naphthenate, cobalt naphthenate,iron 2-ethyl hexenoic acetate, dioctyl tin bis-octyl thioglycollic acidester salt, dioctyl tin maleic acid ester salt, dibutyl tin maleic acidpolymer, dimethyl tin mercapto propionic acid salt polymer, dibutyl tinbis-acetyl acetonate, dioctyl tin bis-acetyl laurate, tetrabutyltitanate, tetranonyl titanate and bis-(acetylacetonyl)di-propyltitanate.
 4. The chemical adsorbent solution according to claim1, wherein said alkoxysilane surface active agent comprises afluorocarbon group.
 5. The chemical adsorbent solution according toclaim 1, wherein said silane surface active agent comprising afluorocarbon group is a substance represented by one of the followingtwo formulas:

    CF.sub.3 --(CF.sub.2).sub.n --(R).sub.m --SiX.sub.p (OA).sub.3-p

wherein n is 0 or an integer, R represents an alkylene group, vinylenegroup, ethynylene group, arylene group, or a substituent containing asilicon atom or oxygen atom, m is 0 or 1, X represents an hydrogen atom,alkyl group, alkoxy group, fluorine-containing alkyl group orfluorine-containing alkoxy group, A represents an alkyl group, and p isan integer of 0, 1 or 2; and

    CF.sub.3 COO--(CH.sub.2).sub.w --SiX.sub.p (OA).sub.3-p

wherein w is an integer, X represents an hydrogen atom, alkyl group,alkoxy group, fluorine-containing alkyl group or fluorine-containingalkoxy group, A represents an alkyl group, and p is an integer of 0, 1or
 2. 6. The chemical adsorbent solution according to claim 1, whereinsaid non-aqueous solvent is at least one solvent selected from awater-free solvent comprising a hydrocarbon and a water-free solventcomprising a fluorocarbon.
 7. The chemical adsorbent solution accordingto claim 1, wherein said solution mixture has a water content of 10 ppmor less.
 8. The chemical adsorbent solution according to claim 1,comprising 0.1 to 30 parts by weight of said alkoxysilane surface activeagent, 0.0001 to 7.5 parts by weight of said silanol condensingcatalyst, and 62.5 to 99.8999 parts by weight of said activehydrogen-free non-aqueous solvent per 100 parts by weight of saidsolution mixture.